Flexible conduit.



G. A. LUTZ.

FLEXIBLE CONDUIT.

APPLIGATION FILED JUNBG, 1908.

Patented June 28, 1910.

MNM

UNITED sTArEs PATENT oEEioE.

GEORGIE A. LUTZ, OF PLAINFIELD, NEW JERSEY,l ASSIGNOR TO AMERICAN CIRCUL LOOM COMPANY, OF PORTLAND, MAINE, A CORPORATION 0F MAINE.

FLEXIBLE CONDUIT.

Specification of Letters Patent. Patented June 28 1910.

Application filed June 6, 1908. Serial No. 437,116. v

an insulated conductor during the processi of forming the conduit or protector, or` the conductor may be drawn into the conduit or tube after the latter is made.

In carrying out fiy invention I provide a .strip of suitable .flexible material, such as steel, or the like, and corrugate the same transversely, the corrugations preferably passing across the strip at an oblique angle to the longitudinal axis of the stri and such corrugated strip is bent into tubu ar or other suitable hollow forni, and to hold the same in such hollow or tubular forni I providea binder encircling the same, such as a wire or strip wound around the tube. vWith the corrugations formed in the strip .Lt an angle to the longitudinal axis of the latter, and the latter bent into tubular form with its edges abutting, the corrugations of the tube so formed will extend along the tube in a spiral direction, and thus the binder ymay be wound spirally in the grooves or on the projections of the tube. The interior of the conduit or tube formed as above described will be substantially smooth throughout without sharp edges or corners' liable to injure the insulation of the conductor when the latter is drawn through thetube.

Reference-is lto be had to the accompanying drawiii s forming part hereof, wherein,

Figure l 1s a partly broken side view of a flexible conduit or tube constructed in accordance with my improvements, shown containing an insulated conductor, Fig. 2 is a cross section on the line 2, 2, in- Fig. 1,-uthe conductor being removed, Fig. 3 is a similar view on the line 3, 3, in Fig. 1, showing the conductor, Fi 4 is a detail view illustrating the manner o forming the conduit, and Fig.

5 is a side view partly broken of a modification.

In carrying out my invenion take a strip a of suitable metal, such as steel, and corrugate the saine transversely, preferably at an oblique angle to the longitudinal axis of the strip, and roll or bend such corrugated strip into tubular or hollow form, as shown in dotted lines in Fig. 4:, so that the edges of the tubular strip preferably abut. The corresponding projections la and depressions 1b of the tube 1 thus formed meet iii such manner as to provide spiral projections and depressions around the tube, and the inner surface of the tube is substantially smooth.

To close and protect. the joint 2 between the longitudinal meeting edges I have shown in Figs. l, 2 and 3 an outer tubular covering 3 made in manner similar to that described with respect to tube l, and fitting closely over the latter, withV the correspondingprojections and depressions 3a, 3b, alining with the corresponding projections and depressions la, 1b, butthe'joint 4 is out of line with the joint 2 of the inner tube, and preferably on the side of the tube or conduit opposite joint 2, as shown in Fig. 2.

To hold the outer tube or protector 3 upon the inner tube l I have shown a binder 5, in the form of a wire, Wound spirally around the tube or conduit and entering the depiessions 3b. l

The conduit or protecting tube described may be formed directly upon the insulation 6 of conductor 7, or the flexible tube or conduit inay be made independently and the conductor subsequently drawn in the same as desired.

Instead of providing the outer flexible tubular cover 3 as above described whereby the flexible tube or conduit is of substantially two thicknesses of metal, I may provide the tube in a single 'corrugated strip, in which case while vthe binder 5 in the form of a wire may be used as before described, I preferably provide the binder in the forni yof a stiip of metal 5a, as shown in Fig. 5,

of my invention is that such tube, conduit or protector may be made of indefinite lengths so as to avoid the use of couplings between adjacent tubes or conduits as much as possible. Furthermore, by making the tube or conduit, or the inner portion thereof t of a single strip of material there will be l infr with each other near their edges.

aving now described my invention what I claim is: l

l. A flexible tube comprising inner and outer strips bent into tubular form around their longitudinal axes and having corrugations, the joint of one strip being out of line with the joint of the other strip.

2; A flexible tube vcomprising inner and outer strips bent into tubular form around their longitudinal aXes and having corrugations, thejoint of one strip being out of line with the joint of vthe other strip, and a binder encircling the outer strip.

v3. The combination of an insulated conductor, with a protecting covering comprising a strip bent around its longitudinal axis and surrounding the insulation and provided with corrugations extending around.v the strip, an outer longitudinally disposed strip provided with corrugations, the longitudinal joints of said strips being out of alineinent, and means to retain said strips upon said conductor. l

4. A flexible tube comprising a metal strip of greater length than width having corrugations at an angle to its longitudinal axis and bent in tubular form, and an outer metal tube having corrugations bent around the first named tube, the joints of said tubes i being out of line. l

5. A flexible tube comprising inner and outer strips having corresponding corrugations, said strips being bent into tubular form around their respective longitudinal axes, the corrugations of one strip matching the corrugations of the other strip, the joint at the longitudinal edges of one strip breaking joint with the longitudinal edges of the other strip. v

Signed at New York city, in the county of New York, andState of New York, this 27th day of May, A. D. 1908.

GEORGE A. LUTZ.

Witnesses:

T. F. BOURNE, MARIE F. WAINRIGHT. 

